Antimony Adsorption Characteristics And Migration Behavior Of Two Different Types Of Soil

In recent years, industry is developing rapidly, mining and smelting industry is thriving, a series of behavior makes the situation of soil pollution especially heavy metal pollution becomes worse and worse. As we all knows, the soil has strong adsorption to the heavy metal ions, traditionally heavy metals in the soil is not moving, which means that they tend to accumulate in soil. But because the soil is a very complex system, when environmental conditions change, there will occur a series of physical, chemical and biological reaction process, heavy metals will move to soil depth, soil pollution range will increase, even the pollution of groundwater. Therefore, the research of heavy metals in the soil under the condition of different physical and chemical adsorption desorption and migration transformation rule is of important theoretical significance for preventing and controling of environmental pollution and repair contaminated soil.Antimony (Sb) is a kind of poisonous metalloid element natural existence. In the periodic table, it is in the same group with arsenic. Our country is the main producer of antimony in the world. The mining, smelting, etc. of antimony ore, makes a lot of antimony and its compounds into the soil and water.In this paper, we choose metalloid antimony as the research object, analyzes the adsorption characteristics of antimony in red soil and brown calcareous soil from south China under different concentration, different pH, different reaction time; To analyze REDOX point conditions, the migration regularity of antimony, we were prepared by iron, quartz sand, further discusses the different pH conditions of antimony in coated iron migration regularity and mechanism of quartz sand, reveals the migration patterns and mechanism of action of antimony in red soil and brown calcareous soil;. The experimental results showed that:1) The adsorption quantity of Sb(V)(13.8μmol g-1) and adsorption speed (0.58μmol g-1h-1) in acid red soil were greater than brown calcareous soil (9.19μmol g-1;0.38μmol g-1h-1), the adsorption of Sb(V) in red soil surface is a rapid irreversible process.2) Analysis of adsorption process under different pH conditions came to the conclusion that the lower the pH, the higher the content of H+, antimony in soil existed mainly in acid radical ion form, negatively charged, so larger amount of adsorption.3) Comparing the fitting effect of four kinds of dynamic equation on the experimental results, we found that for red soil, under the condition of high concentration the fitting of Elovich equation(R.2=0.96) is better. Under the condition of low concentration the fitting of pseudo-second-order kinetics equation (R.2=0.97,1.00) is better. For the brown calcareous soil, under three kinds of concentration, the fitting of two-constant equation (R2=0.96,0.94,0.93) is better.4) The penetration curve of Antimony in coated iron quartz sand shows that the higher the pH, the more obvious asymmetry, trailing phenomenon is more serious. Heavy metal migration was slow in the condition of low pH value, that is the later flow, lower peak. This suggests that if somewhere in acid rain or high salt waste water pollution, can make the soil of heavy metal ions adsorption desorption rate reduced, so that the migration of antimony dimished. Under different experimental conditions, the breakthrough curve of heavy metal left half steep and right half relatively flat and trailing, the penetration process of red soil is longer than brown calcareous soil; After once penetrating, stoping a week or so, once again, the breakthrough curve peak of antimony in red soil increased significantly, trailing phenomenon diminished significantly, which showed that adsorption ability dropped, desorption is obvious.5) In dynamics experiment Antimony mainly combined with Fe, Al oxidation states and residue left in the two kinds of soil, obligate and no obligate adsorption form is very low, which also suggests that antimony in soils is priority to irreversible holding. Antimony in migration experiments mainly combined with Fe and Al oxidation states reserved in soil, the other three forms of content are relatively low, which showed that the elution is complete.